Reaction products of amines and various carboxylic acylating agents are known. These derivatives are useful as lubricating oil additives, particularly as dispersing agents. Common dispersing agents typically do not provide an anti-wear or anti-oxidant benefit and thus, usually are not referred to as multifunctional additives.
In recent years, the need for reduced emissions from motor vehicles has resulted in the use of new catalyst technology. This new technology is sensitive to additive elements present in conventional lubricants, such as sulfur and phosphorus. These elements are typically present due to the use of conventional wear and oxidation inhibitors. The metal surfaces of machinery or engines operating under heavy loads wherein metal slides against metal may undergo excessive wear or corrosion. Often the lubricants used to protect the metal surfaces deteriorate under such heavy loads and as a result, do not prevent wear at the points of metal to metal contact. Consequently, the performance of the machine or engine will suffer, and in aggravated cases the machine or engine may become completely inoperative.
Therefore, a need exists for low or non sulfur or phosphorus containing anti-wear and anti-oxidants. A particular need is for the preparation and identification of multifunctional additives, such as additives that combine wear, oxidation, and dispersancy.
U.S. Pat. No. 3,714,045 discloses a lubricating composition containing lubricants and a polyimide produced by reacting stoichiometric amounts of (1) a heteropolymer produced by reacting an olefin with maleic anhydride in the presence of a free radical initiator with (2) a primary arylamine.
U.S. Pat. No. 4,522,736 discloses a reaction product formed by reacting an alkenyl succinic acid or anhydride with first a diaromatic amine and then an alkanol amine. Likewise, U.S. Pat. No. 4,895,549 discloses a reaction product prepared by reacting an alkenyl succinic compound with an arylamine and a hindered alcohol.
U.S. Pat. No. 5,112,507 discloses a copolymer of an unsaturated acidic reactant and a high molecular weight alkylvinylidene olefin having a sufficient number of carbon atoms such that the resulting copolymer is soluble in lubricating oil and wherein the olefin has at least about one branch per two carbon atoms along the chain.
U.S. Pat. No. 4,234,435 discloses the use of carboxylic acid acylating agents which are derived from polyalkenes such as polybutenes and a dibasic carboxylic reactant such as maleic or fumaric acid. The acylating agents are further characterized by the presence, within their structure, of at least 1.3 groups derived from a dibasic carboxylic reactant for each equivalent weight of the polyalkene. The acylating agents are then further reacted with polyamines or polyols to produce derivatives that are useful as lubricant additives or as intermediates to be subjected to post treatment with various other chemical compounds.
U.S. Pat. No. 5,454,962 discloses a dispersing agent made by reacting aminoguanidine with a hydrocarbyl-substituted succinic acid or anhydride in a mole ratio of from about 0.4 to about 1.2 moles of the aminoguanidine per mole of the succinic acid compound.